Guest v Guest - Where are we now?

National law firm Clarke Willmott LLP represented Andrew Guest at the High Court trial, the Court of Appeal hearing and the Supreme Court appeal. Here Esther Woolford, partner and head of the agriculture sector at Clarke Willmott, looks back at the case and others that have been heard since. 

The principle of estoppel ensures fairness where a party has relied on a promise to their detriment. Proprietary estoppel, a subset of this principle, applies to assurances regarding rights or interests over property or land. It is frequently invoked in cases where a landowner’s promise is disputed.

On 19 October 2022, the Supreme Court issued its decision in Guest v Guest, a case that has since been heavily cited in proprietary estoppel claims. However, has it provided clarity or introduced further complexity?

The case and judgment

Guest v Guest [2022] UKSC 27 involved Tump Farm, a dairy farm in Monmouthshire, which had been owned and operated by the Guest family for years. David and Josephine Guest had three children: Andrew, Ross, and their sister.

Andrew had worked on the farm for over three decades for minimal wages, based on his parents’ assurances that he would inherit a share of the farm. However, after a family dispute in 2015, his parents disinherited him and terminated his involvement in the business. He pursued legal action based on proprietary estoppel, arguing that he had relied on these promises to his detriment.

To succeed in a proprietary estoppel claim, a claimant must establish:

• A promise, assurance, or representation made by the promisor to the promisee
• Detrimental reliance by the promisee

The Supreme Court determined that the remedy should be framed around Andrew’s expectation of inheritance rather than a purely detriment-based approach. The judgment emphasised that proprietary estoppel remedies should address the promisor’s unconscionable conduct by fulfilling the promisee’s reasonable expectations.

Impact on subsequent cases

Since the ruling, proprietary estoppel claims continue to arise, with Guest v Guest being frequently referenced. In Spencer v Spencer [2023] EWHC 2050 (Ch), the High Court reaffirmed that courts must consider how to satisfy an equity claim in light of the Supreme Court's guidance. Mr Justice Rajah stated that prior cases must now be read through the lens of Lord Briggs’ ruling in Guest v Guest.

Similarly, Cleave v Cleave [2024] EWHC 2492 (Ch) and Armstrong v Armstrong [2024] EWHC 2989 (Ch) further reinforced this framework. The courts continued to favour claimants who had devoted their lives to farming under assurances of inheritance. In Winter v Winter [2024] EWCA Civ 699, the Court of Appeal reiterated the long-standing principle that detriment includes non-financial sacrifices made by those who commit their working lives to a family business.

Where does this leave proprietary estoppel?

While Guest v Guest has shaped the legal landscape, it has not resolved all ambiguities in proprietary estoppel claims. The Supreme Court clarified that expectation-based remedies are appropriate, but the assessment of detriment remains nuanced.

This means that while the case provides some guidance, expert legal insight remains crucial in determining the likely outcome of disputes. The overall issue of conscionability still requires careful consideration, ensuring that each case is assessed on its unique facts and circumstances.